We thank Tamura et al. 1 for their thought-provoking letter indicating that there are indeed still a lot of questions to be answered about the recurrence of primary sclerosing cholangitis (PSC). They suggested that a comparison of risk factors and rates of recurrence in living and deceased donor grafts may help shed light on the pathogenesis of this condition and inform outcomes. Tamura et al. cited 2 studies suggesting that recipients of living donor liver grafts have higher and more accelerated rates of recurrence than recipients of deceased donor grafts, although graft survival is not different.
The literature on recurrent presumed autoimmune diseases is confusing because centers use different methods for assessing patients, different immunosuppressive protocols, and different diagnostic criteria. 2 The 2 studies quoted by Tamura et al. 1 include relatively small numbers of patients (37 in total) with relatively short follow-up (medians of 31 and 42 months). 3,4 There are other possible reasons for any differences between the recipients of grafts from deceased donors and the recipients of grafts from living donors: There may be a difference in risk factors, in that inflammatory bowel disease is more common in Western PSC patients than Eastern PSC patients, 5,6 and there is more likely to be a shared genetic background between graft and host in living donor liver transplantation. Furthermore, in living donor liver transplantation, there are shorter ischemic times, a lower likelihood of adverse risk factors for the graft (less steatosis, younger donor age, and less brain injury), and different anatomical anastomoses (the anatomy is comparable only to split livers, which accounted for 7% of the grafts in our series without any recurrence). 7 For these reasons, we are very cautious about drawing any conclusions from the apparent greater risk of recurrence of PSC in living donor transplant recipients. Others have reported the impact of genetic factors 8-10 on the recurrence of PSC after deceased donor liver transplantation, and this may account for multiple recurrences in some patients of our series. 7 We would welcome larger and collaborative studies with common protocols to define more clearly the rates of recurrence, impact on graft survival, and risk factors. We are grateful to Tamura and colleagues for their interest.